The speed of gear pumps is limited by cavitation. By increasing an inlet pressure of pumps, pumps may operate greater speeds without causing cavitation. As the speed of gear pumps is limited by the inlet pressure, gear pumps are commonly used with cumbersome boost pumps, pressurized tanks and the like to feed pressurized fluid to the inlet. Such techniques, however, present problems were space or weight may be an issue, and may also present unwanted costs and complexity. There is therefore a need for improvement.